1. Field of the Invention
The present invention relates to cargo transportation. More specifically, the present invention relates to the movement of cargo between the various transportation modes. More specifically yet, the present invention relates to apparatus and a method for moving cargo into and out of a cargo container at a shipping terminal.
2. Description of the Prior Art
For the past fifty years, much of worldwide shipping of goods in the general cargo liner business has taken place with the aid of cargo containers. The containerized cargo method involves the filling of a container with goods at the goods' point of origin and then leaving the goods in that container until they reach their point of destination. In general there will be a number of intermediate way-stations to which the containers are taken. Key among these way stations are usually the shipping terminals at which the cargo-filled container begins and concludes, respectively, the ocean- or sea-going segment of its journey. For the sake of definitiveness in this discussion, these shipping terminals will be taken to be terminals for ocean-going cargo ships, that is, marine terminals.
The container in question is usually of a standardized size and shape, usually either 20 or 40 feet in outside length, with an outside width of 96 inches and a usual outside height of 8.5 feet. In general, the container is filled, also called “stuffed”, with numerous items, on pallets or not. This “stuffing” is, as stated, generally carried out at the point of origin by a combination of manual and machine operations, using fork-lifts and the like. Thus, the stuffing operation can be a tedious and often dangerous operation for the workers and one that always carries a certain risk of damaging the container itself.
The container has no rollers or other means to make it easily movable from one location to the next. It, therefore, requires a rollable chassis on which to be moved, for example, from the point of delivery at a terminal to the point where it is going to be loaded onto a ship.
At the conclusion of the ocean voyage, the process is reversed: the cargo-filled container is lifted from ship to marine-side, ultimately to be moved to and placed on ground transportation. Finally, with perhaps an intermediate stop, the cargo-filled container arrives at its point of destination where the container is emptied (“stripped”) of its goods, again through a combination of manual and mechanized effort. Finally, the empty container is taken back to the overseas terminal.
The usual situation is that, at the point of destination for the goods of a particular container, there are no goods waiting to be loaded into the container for its return trip. Consequently, most containers return empty to the marine terminal. This is an inefficient use of transportation equipment, be it land-, air-, or ocean-based. There is an additional built-in disadvantage where trucks are concerned, regardless of whether the container is being transported filled or empty, and that is that the size of containers, standardized decades ago at 10, 20, 30 or 40 feet, is smaller than the size allowed to be pulled on the highways today. The modern semi-trailer in the USA has an outside width of 102 inches and, commonly, a length of 53 feet. Thus, the trailer-trailer is often under-utilized, pulling a 20 or 40 foot container when it has a pulling capacity for 53 feet semi trailer. This means that the trucking industry significantly under-utilizes the highways by having trucks pull a lower shipping volume than allowed, yet overloads the highways by using more trucks than are necessary for the volume of goods being transported.
As can be seen, many disadvantages are associated with conventional containerized shipping. In addition to the ones set out above and to be summarized below, another even more significant one needs to be added, one connected to the dynamics of shipping. To see this, picture the cargo vessel as having a certain number of slots (also called cells) for containers. To maximize the use of assets tied up in this vessel, it must, to the extent practicable, be continually engaged in crossing the ocean with a full load of cargo, that is, fully loaded with filled cargo containers and with minimum time spent in port. Even ignoring container loss due to damage during the inland stuffing, stripping, and transportation, it is estimated that for this continual ocean-going activity to be maintained there must be a total of five containers to “support” every container slot on a ship. It is clear, for example, that within the 24-72 hour turn-around time of a ship in port, there must be a full container available at the terminal to take the place of the full container just off-loaded from the arriving ship. Furthermore, since the land shipment round trip often takes more time than the ocean round trip, there must already be a third filled container in transit toward the terminal as the re-loaded ship departs. In addition and as noted above, the full container that arrives at its destination and is stripped will not in general have goods ready at that point for re-stuffing; it must therefore be carried empty to another source of goods, or be returned empty to the terminal. And so forth. Moreover, the volume of cargo trade is almost always physically imbalanced and, as a result, containers must frequently be “repositioned” that is, moved as empty containers from a location of lower volume to a trading location of higher volume. This “repositioning” is a significant factor in the high cost of the present method of transporting cargo.
The need for such a large number of “support” containers for each container slot has a number of costs in addition to that associated with having capital tied up in the containers. These containers must be stored and staged somewhere during their transit, full or empty. This means that valuable real estate is taken up as an inherent feature of the present cargo transport method. Furthermore, to address the damage problem, the more containers there are, the more containers are damaged each year to the point where they need to be replaced. This damage occurs as a result of the necessity to shuffle containers from one location to another, that is, they are damaged while being moved on and off rolling stock, while being moved and stacked in storage areas, etc.
In short, the basic idea of 50 years ago, introduced to reduce perceived widespread loss in shipment, no longer works economically in the modern world. A number of attempts have been made to “patch” the problem. These include the following. A method and apparatus for loading automobiles into a cargo container are taught by Bates et al. (U.S. Pat. No. 4,919,582). Apparatus and methods for containerizing and de-containerizing a load are taught by Harp (U.S. Pat. No. 4,832,560; 1989). Similar apparatus is taught by Harp (U.S. Pat. No. 5,044,866; 1991). Harp (U.S. Pat. No. 5,129,778; 1992),teaches a method and assembly for “one-step” loading and unloading, using essentially the invention taught in Harp '560 and Harp '866. An adjustable load-carrying apparatus for fully utilizing transport enclosure space is taught by Halpin et al. (U.S. Pat. No. 5,454,672; 1995). Nevertheless, none of these prior art solutions really solves the problems set out above.
Therefore, what is needed is a way to reduce the costs, human and economic, inherent in the container-stuffing and -stripping of the present shipping process. What is further needed is a way to reduce the inefficiencies inherent in the mis-fit between container size and cargo-space of land-transportation means. What is yet further needed is a way to reduce the total number of containers needed to support each container slot of a working cargo ship, thereby reducing the total world container inventory, increasing asset utilization of marine terminals and inland transportation, and optimizing the infrastructure.